/*
* Eurotech CPU-1220/1410 on board WDT driver
*
* (c) Copyright 2001 Ascensit <support@ascensit.com>
* (c) Copyright 2001 Rodolfo Giometti <giometti@ascensit.com>
* (c) Copyright 2002 Rob Radez <rob@osinvestor.com>
*
* Based on wdt.c.
* Original copyright messages:
*
* (c) Copyright 1996-1997 Alan Cox <alan@redhat.com>, All Rights Reserved.
* http://www.redhat.com
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
* warranty for any of this software. This material is provided
* "AS-IS" and at no charge.
*
* (c) Copyright 1995 Alan Cox <alan@lxorguk.ukuu.org.uk>*
*/
/* Changelog:
*
* 2002/04/25 - Rob Radez
* clean up #includes
* clean up locking
* make __setup param unique
* proper options in watchdog_info
* add WDIOC_GETSTATUS and WDIOC_SETOPTIONS ioctls
* add expect_close support
*
* 2001 - Rodolfo Giometti
* Initial release
*
* 2002.05.30 - Joel Becker <joel.becker@oracle.com>
* Added Matt Domsch's nowayout module option.
*/
#include <linux/config.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/fs.h>
#include <linux/ioport.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/init.h>
#include <asm/io.h>
#include <asm/uaccess.h>
#include <asm/system.h>
static unsigned long eurwdt_is_open;
static int eurwdt_timeout;
static char eur_expect_close;
/*
* You must set these - there is no sane way to probe for this board.
* You can use eurwdt=x,y to set these now.
*/
static int io = 0x3f0;
static int irq = 10;
static char *ev = "int";
#define WDT_TIMEOUT 60 /* 1 minute */
#ifdef CONFIG_WATCHDOG_NOWAYOUT
static int nowayout = 1;
#else
static int nowayout = 0;
#endif
module_param(nowayout, int, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
/*
* Some symbolic names
*/
#define WDT_CTRL_REG 0x30
#define WDT_OUTPIN_CFG 0xe2
#define WDT_EVENT_INT 0x00
#define WDT_EVENT_REBOOT 0x08
#define WDT_UNIT_SEL 0xf1
#define WDT_UNIT_SECS 0x80
#define WDT_TIMEOUT_VAL 0xf2
#define WDT_TIMER_CFG 0xf3
module_param(io, int, 0);
MODULE_PARM_DESC(io, "Eurotech WDT io port (default=0x3f0)");
module_param(irq, int, 0);
MODULE_PARM_DESC(irq, "Eurotech WDT irq (default=10)");
module_param(ev, charp, 0);
MODULE_PARM_DESC(ev, "Eurotech WDT event type (default is `int')");
/*
* Programming support
*/
static inline void eurwdt_write_reg(u8 index, u8 data)
{
outb(index, io);
outb(data, io+1);
}
static inline void eurwdt_lock_chip(void)
{
outb(0xaa, io);
}
static inline void eurwdt_unlock_chip(void)
{
outb(0x55, io);
eurwdt_write_reg(0x07, 0x08); /* set the logical device */
}
static inline void eurwdt_set_timeout(int timeout)
{
eurwdt_write_reg(WDT_TIMEOUT_VAL, (u8) timeout);
}
static inline void eurwdt_disable_timer(void)
{
eurwdt_set_timeout(0);
}
static void eurwdt_activate_timer(void)
{
eurwdt_disable_timer();
eurwdt_write_reg(WDT_CTRL_REG, 0x01); /* activate the WDT */
eurwdt_write_reg(WDT_OUTPIN_CFG, !strcmp("int", ev) ? WDT_EVENT_INT : WDT_EVENT_REBOOT);
/* Setting interrupt line */
if (irq == 2 || irq > 15 || irq < 0) {
printk(KERN_ERR ": invalid irq number\n");
irq = 0; /* if invalid we disable interrupt */
}
if (irq == 0)
printk(KERN_INFO ": interrupt disabled\n");
eurwdt_write_reg(WDT_TIMER_CFG, irq<<4);
eurwdt_write_reg(WDT_UNIT_SEL, WDT_UNIT_SECS); /* we use seconds */
eurwdt_set_timeout(0); /* the default timeout */
}
/*
* Kernel methods.
*/
static irqreturn_t eurwdt_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
printk(KERN_CRIT "timeout WDT timeout\n");
#ifdef ONLY_TESTING
printk(KERN_CRIT "Would Reboot.\n");
#else
printk(KERN_CRIT "Initiating system reboot.\n");
emergency_restart();
#endif
return IRQ_HANDLED;
}
/**
* eurwdt_ping:
*
* Reload counter one with the watchdog timeout.
*/
static void eurwdt_ping(void)
{
/* Write the watchdog default value */
eurwdt_set_timeout(eurwdt_timeout);
}
/**
* eurwdt_write:
* @file: file handle to the watchdog
* @buf: buffer to write (unused as data does not matter here
* @count: count of bytes
* @ppos: pointer to the position to write. No seeks allowed
*
* A write to a watchdog device is defined as a keepalive signal. Any
* write of data will do, as we we don't define content meaning.
*/
static ssize_t eurwdt_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
if (count) {
if (!nowayout) {
size_t i;
eur_expect_close = 0;
for (i = 0; i != count; i++) {
char c;
if(get_user(c, buf+i))
return -EFAULT;
if (c == 'V')
eur_expect_close = 42;
}
}
eurwdt_ping(); /* the default timeout */
}
return count;
}
/**
* eurwdt_ioctl:
* @inode: inode of the device
* @file: file handle to the device
* @cmd: watchdog command
* @arg: argument pointer
*
* The watchdog API defines a common set of functions for all watchdogs
* according to their available features.
*/
static int eurwdt_ioctl(struct inode *inode, struct file *file,
unsigned int cmd, unsigned long arg)
{
void __user *argp = (void __user *)arg;
int __user *p = argp;
static struct watchdog_info ident = {
.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
.firmware_version = 1,
.identity = "WDT Eurotech CPU-1220/1410",
};
int time;
int options, retval = -EINVAL;
switch(cmd) {
default:
return -ENOIOCTLCMD;
case WDIOC_GETSUPPORT:
return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
case WDIOC_GETSTATUS:
case WDIOC_GETBOOTSTATUS:
return put_user(0, p);
case WDIOC_KEEPALIVE:
eurwdt_ping();
return 0;
case WDIOC_SETTIMEOUT:
if (copy_from_user(&time, p, sizeof(int)))
return -EFAULT;
/* Sanity check */
if (time < 0 || time > 255)
return -EINVAL;
eurwdt_timeout = time;
eurwdt_set_timeout(time);
/* Fall */
case WDIOC_GETTIMEOUT:
return put_user(eurwdt_timeout, p);
case WDIOC_SETOPTIONS:
if (get_user(options, p))
return -EFAULT;
if (options & WDIOS_DISABLECARD) {
eurwdt_disable_timer();
retval = 0;
}
if (options & WDIOS_ENABLECARD) {
eurwdt_activate_timer();
eurwdt_ping();
retval = 0;
}
return retval;
}
}
/**
* eurwdt_open:
* @inode: inode of device
* @file: file handle to device
*
* The misc device has been opened. The watchdog device is single
* open and on opening we load the counter.
*/
static int eurwdt_open(struct inode *inode, struct file *file)
{
if (test_and_set_bit(0, &eurwdt_is_open))
return -EBUSY;
eurwdt_timeout = WDT_TIMEOUT; /* initial timeout */
/* Activate the WDT */
eurwdt_activate_timer();
return nonseekable_open(inode, file);
}
/**
* eurwdt_release:
* @inode: inode to board
* @file: file handle to board
*
* The watchdog has a configurable API. There is a religious dispute
* between people who want their watchdog to be able to shut down and
* those who want to be sure if the watchdog manager dies the machine
* reboots. In the former case we disable the counters, in the latter
* case you have to open it again very soon.
*/
static int eurwdt_release(struct inode *inode, struct file *file)
{
if (eur_expect_close == 42) {
eurwdt_disable_timer();
} else {
printk(KERN_CRIT "eurwdt: Unexpected close, not stopping watchdog!\n");
eurwdt_ping();
}
clear_bit(0, &eurwdt_is_open);
eur_expect_close = 0;
return 0;
}
/**
* eurwdt_notify_sys:
* @this: our notifier block
* @code: the event being reported
* @unused: unused
*
* Our notifier is called on system shutdowns. We want to turn the card
* off at reboot otherwise the machine will reboot again during memory
* test or worse yet during the following fsck. This would suck, in fact
* trust me - if it happens it does suck.
*/
static int eurwdt_notify_sys(struct notifier_block *this, unsigned long code,
void *unused)
{
if (code == SYS_DOWN || code == SYS_HALT) {
/* Turn the card off */
eurwdt_disable_timer();
}
return NOTIFY_DONE;
}
/*
* Kernel Interfaces
*/
static struct file_operations eurwdt_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = eurwdt_write,
.ioctl = eurwdt_ioctl,
.open = eurwdt_open,
.release = eurwdt_release,
};
static struct miscdevice eurwdt_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &eurwdt_fops,
};
/*
* The WDT card needs to learn about soft shutdowns in order to
* turn the timebomb registers off.
*/
static struct notifier_block eurwdt_notifier = {
.notifier_call = eurwdt_notify_sys,
};
/**
* cleanup_module:
*
* Unload the watchdog. You cannot do this with any file handles open.
* If your watchdog is set to continue ticking on close and you unload
* it, well it keeps ticking. We won't get the interrupt but the board
* will not touch PC memory so all is fine. You just have to load a new
* module in 60 seconds or reboot.
*/
static void __exit eurwdt_exit(void)
{
eurwdt_lock_chip();
misc_deregister(&eurwdt_miscdev);
unregister_reboot_notifier(&eurwdt_notifier);
release_region(io, 2);
free_irq(irq, NULL);
}
/**
* eurwdt_init:
*
* Set up the WDT watchdog board. After grabbing the resources
* we require we need also to unlock the device.
* The open() function will actually kick the board off.
*/
static int __init eurwdt_init(void)
{
int ret;
ret = misc_register(&eurwdt_miscdev);
if (ret) {
printk(KERN_ERR "eurwdt: can't misc_register on minor=%d\n",
WATCHDOG_MINOR);
goto out;
}
ret = request_irq(irq, eurwdt_interrupt, SA_INTERRUPT, "eurwdt", NULL);
if(ret) {
printk(KERN_ERR "eurwdt: IRQ %d is not free.\n", irq);
goto outmisc;
}
if (!request_region(io, 2, "eurwdt")) {
printk(KERN_ERR "eurwdt: IO %X is not free.\n", io);
ret = -EBUSY;
goto outirq;
}
ret = register_reboot_notifier(&eurwdt_notifier);
if (ret) {
printk(KERN_ERR "eurwdt: can't register reboot notifier (err=%d)\n", ret);
goto outreg;
}
eurwdt_unlock_chip();
ret = 0;
printk(KERN_INFO "Eurotech WDT driver 0.01 at %X (Interrupt %d)"
" - timeout event: %s\n",
io, irq, (!strcmp("int", ev) ? "int" : "reboot"));
out:
return ret;
outreg:
release_region(io, 2);
outirq:
free_irq(irq, NULL);
outmisc:
misc_deregister(&eurwdt_miscdev);
goto out;
}
module_init(eurwdt_init);
module_exit(eurwdt_exit);
MODULE_AUTHOR("Rodolfo Giometti");
MODULE_DESCRIPTION("Driver for Eurotech CPU-1220/1410 on board watchdog");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
